Decoding and realising flapping flight with port-Hamiltonian system theory

Federico Califano, Ramy Rashad, Alexander Dijkshoorn, Luuk Groot Koerkamp, Riccardo Sneep, Andrea Brugnoli, Stefano Stramigioli
2021 Annual Reviews in Control  
A B S T R A C T In this paper we envision how to tackle a particularly challenging problem which presents highly interdisciplinary features, ranging from biology to engineering: the dynamic description and technological realisation of flapping flight. This document explains why, in order to gain new insights into this topic, we chose to employ port-Hamiltonian theory. We discuss how the physically unifying character of the framework is able to describe flapping dynamics in all its important
more » ... cts. The technological and theoretical challenges of flapping flight are discussed by considering the interplay between different topics. First of all, the formal conceptualisation of the problem is analysed. Second, the features and capabilities of port-Hamiltonian framework as the underneath mathematical language are presented. Subsequently, the discretisation of the resulting model by means of structure-preserving strategies is addressed. Once a reliable numerical model is available, we discuss how control actions can be computed based on high-level specifications aiming at increasing the flight performances. In the last part, the technological tools needed to validate experimentally the models and to equip a robotic bird prototype with the necessary sensing and actuation devices are discussed. (F. Califano). way, in a dynamic dance exhibiting partially turbulent phenomena, probably crucial in understanding flight in its full generality. However, the fact that birds learn to fly soon after their birth seems to indicate that, even if the complexity of fluid dynamics is extremely high and sometimes chaotic, it is possible to deal with dynamic interaction patterns and exploit them. Furthermore, many scientists throughout history have let us understand some patterns underlying this complexity, giving the hope of some predictability (Darrigol, 2005) . These observations, together with the exponential increase in performance and efficiency of computational fluid dynamic tools of the last two decades, is producing a new generation of bio-inspired flapping flight UAVs. These aim at gaining new insights on flight mechanisms and translate them into robots through novel design paradigms. In this document we embody the vision of the PortWings project, an ERC advanced grant [Grant Agreement No. 787675] willing to ride the wave of these technological opportunities with the addition of a peculiar modelling strategy: we describe the fluid-solid interaction system starting from first principles, in the framework of port-Hamiltonian system theory and its physically unifying character, which will couple fluid dynamics to dynamically changing surfaces of the wing and their actuation. In fact, in order to decode flapping flight in its whole generality, it is important to avoid the use of quasi-steady aeroelastic models, which made the fortune of fixed-wing technology. Pushing
doi:10.1016/j.arcontrol.2021.03.009 fatcat:kfydtlx6pjbsvfyzji2ie5g3my